Ah I understand now - blame the imagination, I had an image of a perfect machine (that copes with infinity) drawing a perfect circle and it could never complete the circle..
I've had this problem before, such as with
0.9999999...=1 then i realised 1/9 * 9 = 1
which similarly relates to the point that you made!
Well, presumably we can never walk anywhere because you start by walking half the distance, then you walk half THAT distance, then half of that distance, etc, so you can never get to your destination. Blame Zeno (or whoever came up with that concept.) Of course, he never took Physics.
-Dan